Improvement in caloric-engines



H. D. WALLEN,'JR., OF FORT CLUMBUS, Lette/rs Patent No. 83,114, dated ,October 13, 1868.

To all whom 'it concern Be it' known that I, n.1). wALLEN, Jr., @frre Columbus, in the county of vNew York, and State of New York, have invented anew and useful Improve' menti-n Oaloric-Engines; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the ait to make and use the same, reference being had to the accompanying drawings, forming part of this specication, in Which- A Figure l is a side elevation of my invention.

Figure 2 is a plan View of the same. Figure 3 is a detail cross-section through the line a; z, iig. 2. A A

Similar-letters of reference indicate corresponding parts.

The object of this invention is to provide hot-air engines which will Work With better results than those heretofore made. Y

The general features ofthe invention consist in the employment of two parallel cylinders, each cylinder being provided with air-heating chambers at each end. The cylinders communicate with each other through suitable ports, opening om the heating-chamber of one cylinder into the adj acentheating-chamber of the other, and theseA ports are provided with valves, the timely operation of which is accomplished by suitable valve-gear.

The pistons are made, by means of any suitable @lost-motion devices, to move and rest alternately; that is to say, one piston' is at rest, either at the top or bottom of the stroke, while the other piston is making the stroke towards the resting piston.

' This arrangement allows time for the air to be received into and heated in the air-chambers at either end ofi vthe cylinders, which is a prominent feature of my invention.

Another advantageous feature obtains in the utilization of the excess of pressure in the first cylinder to assist in actuating the piston of the second or auxiliary cylinder, whereby the expanded air of the first' cylinder escapes into the second heating-chamber, and, by its pressure, assists to actuate the second piston to make its stroke while the irst piston is resting. This operation takes place at eachend vof .the cylinders, so that the pistons are actuated, in both directions, by expanded air.

By expanding the air at both ends ofthe cylinders,- I am enabled to employ a smaller air-pump, in proportion to the capacity of the cylinders, than the caloricengines heretofore made, for one volume of airis drawn into the air-heating chambers at each stroke ofthe pistons, after the manner of a common air-pump. The air thus introduced is augmented by the introduction of compressed air, which escapes from the reservoir, in which it was compressed by the air-pump, and this, being then heated, actuates the piston, as will be shown.

lvalves of the iirst cylinder.

This operation is more specically explained by rei"n 'erence to drawings,'where A is the first cylinder, and

B the second or auxiliary cylinder.

The air-chambers of the cylinders are shown at A A and B B", respectively.

In practice, the air-chambers may be of copper or composition, the better to withstand the action of the viiame by which they are kept heated.

The air-pump F is double-acting, and worked by a crank, L, and rod, I, the crank being on the main driving-shaft, M, of the engine.

The air-pump delivers air, through the pipe E, linto the reservoir C, in which it is kept compressed.

E E are the inductionepipes, which. admit the compressed airfrom the reservoir into the air-chambers A A" of the -rst cylinder, through the eduction-ports It k of the said chambers, whichv ports are provided with any suitable valves.

b b are the valve-levers ofv such valves, and are pivoted at b b, and operated by cams on the shaft M, to

open'and close the said ports. y jj are the. exhaust-valves for the air-chambers.l

- d d are the levers for these latter yalves, and are pivoted at d d', and actuated by cams on the shaft M,

in the ysame manner as the induction-valves,'though at different times.

c' t" are the inductionvalvesfor the second cylinder, and are operated by levers c e, pivoted at e er, and cams Aon the driving-shafts, aslthe other aforesaid levers.

These valves admit the compressed air from the chambers A' A after the completion of the strokeof the first piston.

h h are the exhaust-valves of the second cylinder, andoperate in a manner similar to the' corresponding The operation of these by one volume, (the measure of the cylinder A,) the air'already in the chamber A. The chamber A being constantly heated, the air it now contains is expanded, and the piston is actuated one stroke, leaving its rodat rest.

There is now a pressure of two atmospheres in the iirst cylinder behind the piston, for the chamberl A' was primarily lled with air at the ordinary tension of one atmosphere. This 'was augmented by another and equal volume of air from the reservoir, which raised the tension of the air to two atmospheres. This, being heated to a degree sufficient to expand the air to Vtwice its natural volume, 'gave an initial pressure behind the piston of four atmospheres. When the piston reaches the extent of its stroke, the tension of the behind it has fallen to two-atmospheres.

The irst piston, by means of suitable lost-motion tmlztfiimtt i mechanism, is now made to rest, and the valve 'i is opened, permitting the air in the iirstcylinder to escape into the chamber B of the second cylinder'.

Fie". l-shows the engine at the moment that the first piston has completed its stroke. The valve 'i is being opened to admit air to the chamber of the second cylinder, which contains also one volume oi' air, which is now augmented by one-half' volume of air from the iirst cylinder; the second chamber will then contain one and ahalf volume of air, giving a presslne of one and a half atmosphere. The air now becomes expanded, riving, if the proper heat be applied, an initial tension of three atmospheres, which tension acts to `drive out the second piston.

When the second piston arrives at the end of its stroke, the air which was in the opposite chamber A is augmented b v air from the reservoir, in the manner rst described, and the first piston is driven back while thesecond is resting.

As the iist piston begins to return, the valve j opens, and exhausts the air before the piston, thus leaving the chamber A full of air, `when the said piston has ariived back from where it started, as herein described.

The operation is the same at both ends of the cylinder.

The cams on the shafts `M are so formed and set as to lift the several valves' at certain movements, which movements are governed by the relative position of the pistons. Thus, valve l: opens iirst, and admits a charge or air, (one cylinders meas1uc,) from the reserv ir, and then closes. The piston is driven out, the exhaust-valve j being open to discharge the air before it. Y

When the first piston is out, the valve i opens, and remains open for a portion of the stroke of' the second piston; the exhaust-valve h' being open to discharge the air infront of the second piston. The valves i or fi. are closed when in front of the second piston.

The air-pump is doubleacting, and of the same capacity as the cylinders. J

The reservoir is also of the same capacity as the cylinders, or nearly so, and as it contains primarily one yolume of air, and receives another at each stroke of the pmnp-piston, it will always conta-in at least two volumes of air while the engine is running, but in praetice a pressure of about fou, atmospheres is allowed to collect in the reservoir before the cocks o o are opened to connect it with the iirst cylinder. .As a measure of air is delivered into the reservoir for" one that is discharged therefrom into the cylinder, the proper excess of pressure is maintained in the reservoir to inject a charge or measure of air into the chambers A A, when the valves' kgor 7c are momentarily opened for that purpose.

p is a safety-valve in the reservoiri The lost-motion mechanism', for resting each piston alternately, will now be described.

l? P are rocking-shafts, each having an arm, Q, the rounded end of which works with iinished contact within a suitable recess in its respective cross-head R" of the piston-rods Q, by means of which the rockshafts are oscillated bythe movement of their respective pistons.

The rock-shafts are provided with other arms, R It', which are connected, by rods S S', to the vibrating arms or plates T T, as shown. These latter arms are rigidly aixed to one another, and vibrate together.

U is a fixed plate, haring a rectangular slot, m m' n. n. This rectangular slot is composed of four connected arched slots, the radialA centres of which are the centresV oi' vibration of the rods T and S.

The rod T connects the arm T with the rod S on stud q, the projecting end of which tra-verses in the rectangular slot of the said plate U.

` V is a slotted arm, on the end of the shaft M, and the stud q works in the said slot as `it traverses in the rectangular slot. Motion-is thus communicated to the shaft M.

The arms T T rest alternately for each piston, but the arms R R move and rest with their respective pistons and rocking-shafts.

W W V 'W are the cross-head guides.

The air-pump is supported by the uprights G G.

X is the ily-wheel and pulley, for transmitting the power ot' the engine. y

The red outlines show the positions of the several parts of the lost-motion mechanism, when both pistons are'at the extentof the out-stroke. The other positions of the same, are the positions when both pist-ons are at the end of the return-stroke.

The air-chambers may be heated, in practice, by any of the known dem'ces for such pmpose, but I prefer to employ a coil of pipe, encircling each chamber, and

provided with series oi' burners, so arranged along the coils, that the fla-mes from the said burners will impinge directly upon the chambers, and thus keep them heated. i v Y This form of heating-apparatus will be available for burning gas or petroleum, when properly-c(mstructed burners for each case are employed.

When coal or other similar fuel is employed, annular chambers, encirclingthe air-heating chambers, may be employed to conduct the heat from the fuel, and bring -the heat thereof in contact with the air-chambers.

Having thus described myinvention,

I claim new, and desire to secure by Letters Patentl. The two parallel cylinders A B, when arranged side by side, and provided at both ends with air-heating chambers A A, B B, and the valve-gear to cause the alternate movement and resting of the pistons, all substantially as shown and described.

2. The rock-shafts P P', having aims c R R', the connecting-rods S S' T, and angular lever T', subst-an'- tially as herein shown and described, in combination with and arranged with relation to the shaft M, slotted plate U, slotted arm V, and cross-heads R, as set forth.

The above specification of my invention signed by me, this 8th day of May, 1868.

H. D. WALLEN, J R.

Witnesses ,z

C. B. THOMPSON, ALEX. F. ROBERTS. 

